Hello,

I have two classes KoRisiko and KoMasznahme.
Both do have a one-to-many association to a class named
KoMasznahmenReferenz.
It sould be possible to navigate from KoRisiko via KoMasznahmenreferenz to KoMasznahme and vice versa.

The mapping files are as followes:

<class
name="KoRisiko"
table="T_KO_ART_risiko_DATA"
dynamic-update="false"
dynamic-insert="false"
<id
name="id"
column="ID"
type="long">
<generator class="sequence">
<param name="sequence">TUKO101.SQ_KO_ART_risiko_DATA</param>
</generator>
</id>
<set name="masznahmenReferenzen" lazy="false" inverse="false" cascade="all" sort="unsorted">
<key column="risikoData"/>
<one-to-many class="KoMasznahmenReferenz"/>
</set>
</class>


<class
name="KoMasznahmenReferenz"
table="T_KO_ART_masznahmenReferenz"
dynamic-update="false"
dynamic-insert="false"
>
<id
name="id"
column="ID"
type="long">
<generator class="sequence">
<param name="sequence">TUKO101.SQ_KO_ART_masznahmenReferenz</param>
</generator>
</id>
<many-to-one name="risikoData" class="KoRisikoData" column="risikoData" not-null="false"/>

<many-to-one name="masznahmeData" class="KoMasznahmeData" column="masznahmeData" not-null="false"/>


</class>

<class
name="KoMasznahmeData"
table="T_KO_ART_masznahme_DATA"
dynamic-update="false"
dynamic-insert="false">
<id
name="id"
column="ID"
type="long">
<generator class="sequence">
<param name="sequence">TUKO101.SQ_KO_ART_masznahme_DATA</param>
</generator>
</id>
<!-- uncomment this to avoid exception -->
<set name="masznahmenReferenzen" lazy="true" inverse="false" cascade="all" sort="unsorted">
<key column="masznahmeData"/>
<one-to-many class="KoMasznahmenReferenz"/>
</set>
</class>


Unfortunately an exception is thrown:

net.sf.hibernate.WrongClassException: Object with id: 36 was not of the specified subclass: art.domain.risiko.workshoprisiko.KoWorkshoprisikoCurrentData (loaded object was of wrong class)
at net.sf.hibernate.loader.Loader.instanceAlreadyLoaded(Loader.java:300)
at net.sf.hibernate.loader.Loader.getRow(Loader.java:278)
at net.sf.hibernate.loader.Loader.doFind(Loader.java:159)
at net.sf.hibernate.loader.Loader.loadCollection(Loader.java:602)
at net.sf.hibernate.loader.OneToManyLoader.initialize(OneToManyLoader.java:102)
at net.sf.hibernate.impl.SessionImpl.initialize(SessionImpl.java:2897)
at net.sf.hibernate.collection.PersistentCollection.initialize(PersistentCollection.java:151)
at net.sf.hibernate.collection.PersistentCollection.read(PersistentCollection.java:64)
at net.sf.hibernate.collection.Set.size(Set.java:114)
at art.HibernateTest.testEnitityToObjectToEntityReferenzes(HibernateTest.java:330)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at junit.framework.TestCase.runTest(TestCase.java:166)
at junit.framework.TestCase.runBare(TestCase.java:140)
at junit.framework.TestResult$1.protect(TestResult.java:106)
at junit.framework.TestResult.runProtected(TestResult.java:124)
at junit.framework.TestResult.run(TestResult.java:109)
at junit.framework.TestCase.run(TestCase.java:131)
at junit.framework.TestSuite.runTest(TestSuite.java:173)
at junit.framework.TestSuite.run(TestSuite.java:168)
at junit.framework.TestSuite.runTest(TestSuite.java:173)
at junit.framework.TestSuite.run(TestSuite.java:168)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:392)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:276)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:167)
rethrown as net.sf.hibernate.LazyInitializationException: Failed to lazily initialize a collection: Object with id: 36 was not of the specified subclass: art.domain.risiko.workshoprisiko.KoWorkshoprisikoCurrentData (loaded object was of wrong class)
at net.sf.hibernate.collection.PersistentCollection.initialize(PersistentCollection.java:163)
at net.sf.hibernate.collection.PersistentCollection.read(PersistentCollection.java:64)
at net.sf.hibernate.collection.Set.size(Set.java:114)
at art.HibernateTest.testEnitityToObjectToEntityReferenzes(HibernateTest.java:330)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:324)
at junit.framework.TestCase.runTest(TestCase.java:166)
at junit.framework.TestCase.runBare(TestCase.java:140)
at junit.framework.TestResult$1.protect(TestResult.java:106)
at junit.framework.TestResult.runProtected(TestResult.java:124)
at junit.framework.TestResult.run(TestResult.java:109)
at junit.framework.TestCase.run(TestCase.java:131)
at junit.framework.TestSuite.runTest(TestSuite.java:173)
at junit.framework.TestSuite.run(TestSuite.java:168)
at junit.framework.TestSuite.runTest(TestSuite.java:173)
at junit.framework.TestSuite.run(TestSuite.java:168)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:392)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:276)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:167)
Caused by: net.sf.hibernate.WrongClassException: Object with id: 36 was not of the specified subclass: art.domain.risiko.workshoprisiko.KoWorkshoprisikoCurrentData (loaded object was of wrong class)
at net.sf.hibernate.loader.Loader.instanceAlreadyLoaded(Loader.java:300)
at net.sf.hibernate.loader.Loader.getRow(Loader.java:278)
at net.sf.hibernate.loader.Loader.doFind(Loader.java:159)
at net.sf.hibernate.loader.Loader.loadCollection(Loader.java:602)
at net.sf.hibernate.loader.OneToManyLoader.initialize(OneToManyLoader.java:102)
at net.sf.hibernate.impl.SessionImpl.initialize(SessionImpl.java:2897)
at net.sf.hibernate.collection.PersistentCollection.initialize(PersistentCollection.java:151)
... 20 more

If I uncomment the set statement following the remark in one of the xml files the exception is not thrown.

Is thie exception a mistake on my behalf or not possible as all?

Kindest Regards,

Alexander Thomas

wrong class name in many-to-one,
wrong usage of inverse.
Read the Parent Child relationship manual

sorry -

I suppose you mean I should use
<class name="KoRsikoData"...

instead of
<class name="KoRisiko"...

in order to get the right class name in many-to-one?

That was actually a mistake while transfering (and reducing) my original xml pieces to the forum.

Whatsoever, l changed the inverse attribute to "true" in my original xml.

Unfortunately, I still have the same error message!

I do not want anybody to find stupid mistakes (i.e. typos) in my coding,
but as a last (much aprecaitaed) help it would be nice to be told weather the intended mapping is actually possible with hibernate (this might have been ovelooked due to my obvious typos in the first place...)

Kindest Regards,

Alexander Thomas

Sure it works.
Check the reference guide examples and change them to do what you want.